Key elements of e-diesel system (EDS)

Control unit (Fig. 4.69) is mounted on the right side of the machine. It performs the following functions: to provide the required amount of fuel to maintain speed, cruise control, diagnostics, control function "intake-output" and determine the degree of malfunction of the system.

Inputs received from these sensors (Fig. 4.70): a pointer to the crankshaft position (from the starter), the position of the working gear starter (at the bottom of the gearbox) Position sensors and sensor accelerator pedal position sensor, suction pressure sensor Intake air temperature sensor coolant temperature, fuel temperature sensor discharge (at the pump), brake light, sensor actuation signal ABS, sensor operation status in starter mode, a running engine (for automatic transmission).

The outputs of these sensors run: stop, speed control, switching valve ARF, positioning the discharge valve, diverter valve in an automatic transmission, the state of the operating mode of a diesel engine EDC (light on the instrument panel), controlled air conditioning and performance problems when connecting the device diagnostics.

All the problems in the system are marked diagnosis system in the computer memory. If the problem continues for a long time, trigger warning lights on the instrument panel. Some "mistakes" can correct the control system, but the computer's memory it will remain. The control unit is in a critical situation himself drown him or establish optimum momentum to continue the movement. If the lamp lights ?�EDS?�, must be sent to the body shop because there is only a qualitative diagnosis and repair.

All models are equipped with the new systems, which are controlled by a microcomputer in conjunction with the so-called CAN-bus (Controller Area Network), which serves as a "countable distributive apparatus" and sends signals to the computer. Electronic control is a key element in the system of Common Rail, which will operate without interruption during regular maintenance.

The coolant temperature sensor is screwed into the front portion of the cylinder head and shows the coolant temperature. Resistance at +80 ?� C is 300 ohms at +20 ?� C - 2.5 kW.

The fuel temperature sensor model 220-D is mounted on the pump and in the section of the separation of the shaft position sensor. At 5-cylinder diesel it is at the stop mechanism. This sensor detects the temperature of fuel for the subsequent calculation of its density. It also generates a signal at a failure of the coolant temperature sensor.

The signal from the intake air temperature sensor (Fig. 4.71) is used to calculate the mass of air when adjusting the fuel injection amount correction fuming, the exhaust and charge air pressure control. Resistance at +20 ?� C - about 6 ohms at +40 ?� C - about 2.6 ohms.

Air mass meter (CDI). Information about the weight of the intake air is essential for calculating the fuel mixture in the injection. Regardless of the temperature measurement is carried out as follows. The intake system mounted receiving element (heating plate), which is cooled by receiving the air flow. Depending on the strength of it changes its flow and temperature resistance. Electric resistance value changes is given to the control unit.

The crankshaft position sensor is used to determine the speed and position of the crankshaft. Located on the gearbox housing on the starter.

Four (five at the 5-cylinder engines) segment at the flywheel when the engine is issued to the sensor alternating voltage. The greater the number of turns - the greater the stress. If the segment passes the sensor front edge, there is a positive voltage jump when the heel edge - negative.

Position sensor pinion starter set only in a 5-cylinder models, and indicates the number of revolutions. Located below the gearbox housing.

Fuel sensor (Fig. 4.72). Pump has no direct connection with the accelerator pedal. Fuel gauge installed in a protective housing and is coupled to flexible drive pedal. The sensor mounted: potentiometer RPM, idle contact and return spring. On models with automatic transmission also establishes a modulated pressure valve gear.

The switch of a signal of braking. When braking, the control unit receives a signal, cruise control switches off and gives the command to stop the maximum fuel delivery. This avoids the "run" of the car, even with the wrong accelerator pedal. This happens when you press the clutch pedal.

Switch on the clutch pedal. At 5-cylinder diesel engines by pressing the clutch pedal control unit signals during the shift and intensification of the vibration damper.

The suction pipe pressure sensor is on the left side of the engine compartment through a hose connected to the suction line. The pressure on the suction pipe is necessary for the following functions: limit the maximum load, the exhaust (ARF) and the intake air pressure adjustment. In addition to E 290 TD it shows information for adjusting combustion air of the turbocharger.

Combustion air regulator (TD 290) operates via an electropneumatic valve. Operating principle: magnetic relief valve controls the flow of the charge air compressed air through the valve on the compressor - at the opening of the valve the pressure drops.

Camshaft sensor pump (four-cylinder diesel engine) responsive to longitudinal displacement of the camshaft relative to the drive shaft and consists of a coil with a core.

The core screwed into the hollow camshaft. When the shift shaft core changes the inductance of the coil. This is an important feature for adjusting the amount of fuel supply.

Position sensor cam washer (4-cylinder diesel engine) is also composed of a coil with a core. The core is inserted into the piston. The coil is mounted in the housing distribution pump. Cam ring rotates, it makes reciprocating motion back and forth, thereby changing the inductance of the coil and the signal is controlling the fuel injection control.

Stroke sensor rail (5-cylinder diesel engine) control unit transmits position data fuel control rack. The sensor is built into the speed governor inline pump. When the ignition rail takes "start" position (maximum stroke length of the rack - 19.5 mm). When the position of the rack changes the distance between the coil and short-washer, thereby changing the inductance.